Calix[6]arene Derivatives Bearing Sulfonate and Alkyl Groups as Surfactants in Sc(OTf)3-Catalyzed Mukaiyama Aldol Reactions in Water.

Amphiphilic calix[6]arene derivatives 1a–b were found to be efficient surfactants for Sc(OTf)3-catalyzed Mukaiyama aldol reaction of silyl enol ethers with aldehydes in water. The results indicated that a hydrophobic microenvironment was formed in the reaction system, which is favorable to stabilize some labile silyl enol ethers and thus promotes the reactions.